Sunday, May 29, 2011

When salmonella was sent into space for 12 days aboard the space shuttle Atlantis in September of 2006, it was discovered upon it's return to Earth that the microbes had altered the way in which they express a portion of their genes, as compared to a strain of the bacteria that had remained in the lab here on Earth. The apparent result of this alteration, was that it had become almost three times as likely to kill mice infected with the microbes, than it's Earth-bound counter part. Studies like this were able to clearly show that disease microbes grow faster, and become more virulent, when held in the weightless environment of space.

Which is why, amongst the various cargo carried into space by Endeavor on it's final flight, is a sample of juvenile Bobtail squid. These baby cephalopods were sent up by microbiologist Jamie foster, to determine what effect, if any, the environment has on helpful bacteria, like those which give the squid the ability to generate bioluminescence.

Bobtail squid are a tiny variety of cepholopods which have evolved their ability to generate bioluminescence by forming a symbiotic relationship with a particular species of bacteria called VibiroFischeri, the juvenile squid are exposed to this bacteria shortly after hatching, which take up residence in the animals light organs. Fed on a solution of sugar and amino acids by the squid, the bacteria in turn helps the animal to avoid predators by matching the amount of light hitting the top of it's mantle, thus helping to hide it's silhouette from predators below. Because the animal is not born with the bacteria in it's system, and because the process only involves a single species, unlike the symbiotic relationships human beings form with the thousands of species of bacteria which inhabit our digestive and immune systems, The Bobtail squid seems an ideal candidate for this sort of test.

Preliminary experiments conducted in simulated microgravity on Earth appear to have shown problems with the uptake of bacteria by the squid. And if the shuttle study shows the same result, it would suggest that astronauts' relationships with their own microbes might also be affected.